Question

我有两个sql查询，我需要将它们组合成一个查询以提高效率，但不确定如何做到这一点。基本上我需要查询我的供应商，然后为每个供应商检查以查看列表中是否有多个匹配的记录基于＆＃34;供应商ID＆＃34;，如果是，那么我需要返回供应商名称和ID。以下是我的两个问题：

查询1：

SELECT          s.name, s.id 
FROM            Supplier s

查询2：

SELECT      l.asin, 
            l.id, 
            COUNT(*) c
FROM        Listing l
LEFT JOIN   Product p
 ON         p.id = l.product_id
LEFT JOIN   Supplier s
 ON         p.supplier_id = s.id 
WHERE       (l.matchValidated IS NULL OR l.matchValidated = 0)
AND         s.id = SUPPLIER_ID_GOES_HERE
GROUP BY    l.asin HAVING c > 1);

Answer 1

您已在第二个查询中加入了供应商，因此您只需将供应商名称和ID添加到SELECT和GROUP BY。

SELECT      l.asin, 
            l.id,
            s.name AS supplier_name,
            s.id AS supplier_id, 
            COUNT(*) c
FROM        Listing l
LEFT JOIN   Product p
 ON         p.id = l.product_id
LEFT JOIN   Supplier s
 ON         p.supplier_id = s.id 
WHERE       (l.matchValidated IS NULL OR l.matchValidated = 0)
GROUP BY    l.asin, l.id, s.name, s.id 
HAVING      c > 1;

将两个MySql合并为一个查询

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